Electric brush-holder.



PATENTBD THE. 3, 1903.

H. T. MAKER.

ELEOTRIG BRUSH HOLDER.

APPLICATION FILED NOV. 12, 1902.

N0 MODEL.

@wwm:

UNITED STATES PATENT OFFICE.

HARRY T. MAKER, OF MILWAUKEE, WISCONSIN.

ELECTRIC BRUSH-HOLDER.

SPECIFICATION forming part of Letters Patent No. 719,824, dated February3, 1903. Application filed November 12, 1902. Serial No. 130,962. (Nomodel.)

f0 all whom it mag iconcern:

Be it known that I, HARRY T. MAKER, a citizen of the Dominion of Canada,residing at Milwaukee, in the county ofMilwaukee and State ofl/Visconsimhaveiuvented certain new and useful Improvements in ElectricBrush- Holders, of which the following is a specification, referencebeing bad to the accompanying drawings, forming a part thereof.

This invention relates to holders for carbon or similar brushes. Itsmain objects are to simplify and improve the construction and operationof brush-holders of this class; and it consists in certain novelfeatures of construction and in the arrangement and combinations ofparts hereinafterparticularly described, and pointed out in the claims.

In the accompanying drawings like letters designate the same parts inthe several figures.

Figure l is a vertical longitudinal section on the line 1 1, Fig. 2, ofa brush-holder embodying my improvements. Fig. 2 is a plan view of thesame, the tension-nut being removed; and Fig. 3 is a longitudinalsection on the line 2 2, Fig. 1, through the brush-supporting arm.

The brush-supporting arm or member of the holder consists of a splitcast-metal hub a and a sheet-metal arm b, formed at one end into asleeve 0 to approximately fit the brush (Z and embedded at the oppositeend in the hub a. In the present case the sleeve 0 is of rectangularform to receive and hold an ordinary carbon brush. The sides of the armI) are separated from each other, leaving a space between them openinginto the sleeve 0, as shown in Figs. 2 and 3.

The hub a is formed at the ends with circular bosses e e concentric withits bore, and it is provided with a clamping-screw f, by means of whichit is adjustably secured on a cylindrical stud or rod 9 in the usualmanner.

To take up play between the brushes,which vary more or less inthickness, and the sleeve 0, two adjustable supports or bearings h h areprovided. These supports or bearings may be conveniently stamped out ofsheet metal, and they are guided and held in place by projectionsengaging transverse slots 1' in opposite sides of the sleeve 0 and byscrews jj, threaded therein and passing through similar slots 7c in theside sections or members of the arm 5. Obviously a single adjustablesupport or hearing might be substituted for the two supports orbearings, which, however, can be more readily and cheaply stamped out ofsheet metal.

Z is a tension-arm composed of two parts or sections, which may beconveniently and economically stamped from sheet metal and securedtogether by screws m m. The sections are bent away from each other nearone end and formed With eyes 12 n, which are fitted to turn on thebosses e 6. Between the ends of the arm Z the component sections arebent outwardly in semicylindrical form to produce an opening for thepassage of a tension-spring and to form a seat or bearing for atensionnut. At the free end of the arm Z, which is adapted to bearagainst the end of a brush d, held in the sleeve 0, the parts orsections may be permanently secured together by a rivet 0.

A spiral tension-spring 19, attached at one end to the supporting-arm bin the recess or space between its sides by means of a crosspin q orotherwise, passes through the opening therefor in the tension-arm Z andis provided with a nut 1', which is threaded directly thereon. The pitchof the screw-thread in the nut is greater than the normal pitch of thespiral spring, so that the spring is spread and strained by screwing thenut thereon, and the nut is thus held in place when adjusted withoutother means of locking it.

The arms I) and Z may be made of sheetbrass and the hub a, of some metalor composition whose meltingpoint is somewhat lower than that of brass,so that the arm I) may be cast therein, as indicated in Fig. 3, withoutmelting it. A metal mold maybe conveniently employed for casting thehub, so that it will require little or no machinework to finish it.

The construction herein shown and described is strong, light, simple,and cheap, as the parts require little or no hand or machine work tofinish them and they are easily assembled. The tension device is alsoextremely simple and efiective. Bythreading the tension-nut directly onthe spiral of the spring a greater effective length of spring isobtained than can be obtained within the same compass when thetension-nut is threaded on a screw to which the spring is attached, thescrew in this case reducing the eifective length of the spring.

With the tension device herein shown and described the tension-arm 1 maybe turned back without injuriously straining and affecting theresiliency of the spring. Besides, by reason of its greater effectivelength and increased elasticity, the tension-arm is capable of a widerrange of movement with less variation in the tension of the spring thancould be secured if the spring were connected with the nut by anordinary screw.

Various changes in minor details of construction may be made withoutdeparting from the principle and intended scope of the invention.

I claim- 1. A brushholder comprising a cast-metal hub and a sheet-metalbrush-supporting arm formed at one end with a sleeve for the brush andembedded at the opposite end in said hub, substantially as described.

2. A brush-holder comprising a cast-metal hub formed at the end withcircular bosses, a sheet-metal brush-supporting arm formed at one endinto a sleeve for the brush and embedded at the opposite end in saidhub, and a tension-arm formed of two pieces of sheet metal securedtogether side by side and formed with eyes fitted to turn on saidbosses, substantially as described.

3. A brush-holder comprising a split castmetal hub provided with aclamping-screw and formed at the ends with circular bosses,

' a sheet-metal brush-supporting arm formed at one end with a sleeve andembedded at the opposite end in said hub, a tension-arm composed of twosheet-metal parts which are formed with eyes fitted to turn on saidbosses and are clamped together by screws, said parts being bent awayfrom each other between their ends and forming a bearing for atension-nut and an opening for a tension-spring, and a tension-springattached to said brushsupporting arm, passing through the openingtherefrom in said tension-arm and provided on the opposite sidev thereofwith a nut, substantially as described.

4:. In a brush-holder the combination of a brush-supporting arm providedwith a sleeve for a brush, and an adjustable support attached to saidarm and projecting into one side of said sleeve, substantially asdescribed 5. In a brush-holder the combination of a sheet-metalbrush-supporting arm provided with a hub at one end and formed with asleeve to receive the brush at the other end and brush-supports guidedby transverse slots in opposite sides of said sleeve and adjustablyattached to said arm by screws passing through longitudinal slots in itsside members, substantially as described.

6. In a brush-holder the combination of a brush-supporting arm, atension-arm pivotally connected therewith, a spiral spring attached atone end to said supporting-arm, and a nut having a bearing on saidtension-arm and threaded upon said spring, substantially as described.

7. In a brush-holder the combination of a brush-supporting arm, atension-arm pivotally connected therewith, a spiral spring attached atone end to said supporting-arm and a nut having a bearing on saidtension-arm and threaded upon said spring, whose normal spiral is ofless pitch than the thread of said nut, substantially as described.

8. In a brush-holder the combination of an open brush-supporting armhaving a sleeve at one end to receive and hold the brush, a tension-armpivotally connected with said supporting-arm and having an opening forthe passage through it of a tension-spring, and aspiral tension-springattached at one end to said supporting-arm in the opening between itssides and passing through the opening in the tension-arm, and a nutseated on said tension-arm. and threaded directly on the spiral of saidspring, which is normally of less pitch than the thread of said nut,substantially as described.

In witness whereof I hereto affix my signature in presence of twowitnesses.

HARRY T. MAKER.

\Vitnesses:

CHAS. L. Goss, HENRY WINKENWERDER.

